• Environmental Engineering Research
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• 제25권3호
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• pp.356-365
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• 2020

The aqueous carbonation efficiencies of basic oxygen furnace (BOF) and ladle slags at various pressures, temperatures, and liquid-to-solid (L/S) ratios were investigated to determine optimum conditions. The maximum CO₂ carbonated concentrations in slag (0.584 mmol/g for BOF slag and 1.038 mmol/g for ladle slag) was obtained at 10 bars, 40℃, and L/S = 5 mL/g-dry. The L/S ratio was the most critical parameter for carbonation. The effect of carbonated slag amendment on the immobilization of heavy metals in two field-contaminated soils was also investigated. The immobilization efficiencies evaluated by using the toxicity characteristic leaching procedure (TCLP) and the Standards, Measurements and Testing Programme (SM&T) were above 90% for both raw and carbonated slags for all soils. The TCLP-extractable heavy metals concentrations were below the criteria (5.0, 1.0 and 5.0 g/L for Pb, Cd, and Cr, respectively) after immobilizations with both slags except for Pb in soil B. The SM&T analysis showed the decrease in the exchangeable phase but the increase in residual phase after immobilization with raw and carbonated slags. The results of this study imply the promising potential of the carbonated slags on the immobilization of heavy metals in the field-contaminated soils.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.555-559
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• 2001

A by-product, waste sludge water produced from ready mixed concrete(remicon) factories may affect our environmental contamination if it is discharged without proper waste disposal. In Korea, all waste sludge water has been recycled in the way of mixing water of remicon, but the quality of the concrete then produced can be deteriorated, so it might cause slump loss or irregular compressive strength. In this study, waste sludge water is divided into two parts, remicon sludge and residual water in order to make it's property more stable. Then, the remicon sludge and high-alkaline residual water were used as admixture and alkali activator respectively. In this paper we research about quality of with remicon sludge and residual water and performed the fundamental properties of cement matrix mixed with remicon sludge and residual water.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.79-80
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• 2019

This study was intended to examine the possibility of reducing hydration heat by FA substitution and combination of slag (CGS) from coal gasification power generation (IGCC) with mixed aggregate for concrete. The analysis results showed good results if liquidity increases as the ratio of CGS increases, air volume decreases, and compressive strength is mixed up to 25% in the residual aggregate. The results showed that the heat of hydration was reduced compared to plain due to the boron content of CGS as the CGS substitution rate increased, but it was larger due to the combination with FA substitution. It was found that the heat of hydration was reduced.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 춘계 학술논문 발표대회
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• pp.91-92
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• 2013

The strength of ultra-high-strength concrete can be reduced even if the spalling is prevented at a high temperature. Therefore, in this study, we measured internal temperature history and residual compressive strength using a 300×300×450mm short column specimens which use the fiber(NY 0.15+PP 0.10+SF 0.30vol·%) and respectively silica sand, washed sand, the slag sand. As a result, the temperature history and residual compressive strength are almost similar regardless of the fine aggregate types.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.669-674
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• 2001

Electric Arc Furnace Dust (EAF Dust) Is residual dust produced during the manufacturing of metal products from heavily heated electric arc furnace. Many researches have focused on recycling and reusing EAF Dust for industrial and construction purposes. However, most of these researches were aimed at obtaining useful heavy metal powders by treating toxic metallic materials in EAF Dust. Also, few researches dealt with using EAF Dust as admixture in concrete mixture (i.e., slag dust). In this study, EAF Dust is used as admixture in concrete mixture content considering economical feasibility and construction applicability. The concrete specimens mixed with EAF Dust is then tested in compression and tension to study its strength and ductility as well as its failure mechanism. The compression and tension (by split cylinder test) test results are compared to the results from the specimens without EAF Dust to understand the chemical stability and mechanical characteristic of concrete specimens with EAF Dust. For the experiment, 6 types of admixture added concrete were studied: ⑴Combination of EAF Dust and blast-furnace slag in 1 to 1 ratio, ⑵Combination of EAF Dust and blast-furnace slag in 1 to 2 ratio, ⑶EAF Dust only, ⑷blast-furnace slag only, ⑸fly ash only, and ⑹no admixture. The experimental results show that the strength of EAF Dust added specimen has lower early age strength but higher 28 day strength when compared to other specimens. Also, the Elastic Modulus of EAF Dust is higher(28 days) than other specimens. The study results prove that EAF Dust can be used as an effective admixture in concrete for specific usages.

• 대한토목학회논문집
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• 제43권1호
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• pp.71-77
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• 2023

지속적인 산업 발전에 따라 천연자원 고갈, 폐기물 발생 뿐만 아니라 다양한 기상이변 현상 발생이 빈번해지고 있다. 기후위기 극복과 자원절약을 위해 산업부산물을 재활용하기 위한 노력이 계속되고 있다. 슬래그는 철강산업에서 발생하는 대표적인 부산물로 밀도가 크고 강성이 높은 특징에 따라 아스팔트 콘크리트용 재료로 활용시 강도 증진, 변형 감소를 가져와 소성변형 저항성과 수분 저항성을 향상시키는 특징이 있다. 반면 팽창 특성을 갖고 있어 성토재, 매립재 등 비교적 저부가가치용 재료로 활용되고 있다. 슬래그 재료의 적용처 확대를 위해 슬래그 아스팔트 콘크리트 포장의 균열 저항성 평가 실험을 수행하였다. 간접인장강도 시험결과 슬래그 골재를 사용한 아스팔트 혼합물은 동일 입도의 일반 혼합물 대비 1.13배 이상 높은 값을 보이고 터프니스 또한 1.17대 높아 균열저항성이 향상되는 것으로 나타났다. 또한, 4점 빔 피로 실험과 슬래그 아스팔트 혼합물의 파괴횟수가 20,409회로 일반 혼합물 대비 2배 이상 증가하였으며 Overlay Test 결과 인장하중 잔류율이 4배 이상 높은 값을보여 반복적인 피로에 대한 균열 저항성도 향상되는 것을 알 수 있었다. 이에 따라 슬래그 골재의 사용은 아스팔트 콘크리트 포장의 성능 향상에 다양한 이점이 될 수 있을 것으로 평가된다.

• 한국농공학회논문집
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• 제55권2호
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• pp.59-64
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• 2013

The present study is to evaluate physical and mechanical properties of porous concrete having non cement that mainly causes carbon emission. This study aims to explore eco-friendly concrete technology capable of reducing the amount of carbon emission due to the use of normal cement by substituting it with non cement porous concrete to which alkali-activator and blast-furnace slag powder are impregnated. As experimental variables, 5 %, 6 %, 7 %, 8 %, 9 % and 10 % of alkali-activator were substituted as binders and applied. Testing evaluated in this study were pH value, void ratio, compressive strength and residual compressive strength shown after being immersed in $H_2SO_4$ solution and $Na_2SO_4$ solution. The test results were compared with those tested with the use of porous concrete to which 400 $kg/m^3$ of unit cement amount was applied as binder. In consequence, it was concluded that; as for pH value, it was decreased than was the case in which cement was used, but increased with the more the use of alkali activator; as for void ratio and compressive strength, the mix proportion in which 9 % and 10 % of alkali activator were applied in terms of substitution ratio showed the result similar to the mixture in which 400 $kg/m^3$ of unit cement ratio was applied; and, as for residual compressive strength in the case of being immersed in $H_2SO_4$ solution and $Na_2SO_4$ solution, the compressive strength was increased, thus leading to improved chemical resistance.

• 한국건축시공학회지
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• 제19권5호
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• pp.391-399
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• 2019

본 연구는 국내에 새롭게 도입하고자 시운전중인 석탄가스화복합발전(IGCC)에서 발생하는 석탄가스화 용융슬래그(CGS)를 국내의 부족한 골재자원으로 재활용 가능성을 검토하였다. 즉, 부족한 골재자원확보를 위해 IGCC에서 발생하는 CGS를 빈배합 모르타르인 콘크리트 2차제품용 잔골재로 활용하고자 국내 건설산업에서 가장 많이 사용되고 있는 석산의 부순 잔골재로 양호한 품질의 CSa 및 굵은 입자로 표준입도를 벗어난 CSb와 해사인 SS를 혼합한 혼합잔골재에 CGS를 0~100 % 범위에서 치환하는 것을 검토하였다. 연구결과, CSa 혹은 CSb+SS에 CGS를 25~50% 정도 치환할 경우 골재의 입도측면 및 시멘트 모르타르의 유동성 및 압축강도 측면에서 양호한 결과가 얻어져 활용가능함을 확인할 수 있었다.

• Korean Chemical Engineering Research
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• 제55권2호
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• pp.141-155
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• 2017

이논문에서는 $CO_2$ 활용기술관점에서광물탄산화기술의하나인제철슬래그를이용한침강성탄산칼슘(Precipitated Calcium Carbonate, PCC) 제조 기술의 개발 현황을 고찰하였다. 광물 탄산화 기술의 원리, 특징, 전세계적 개발 현향을 살펴보았고, PCC 제조기술 및 시장동향도 파악하였다. 광물 탄산화는 안정적이고 친환경적인 기술로, 산업 부산물의 경제적 처리를 가능하게 한다. 일반적으로 슬래그중 Ca 용출 및 고액 분리 과정후 상등액과 $CO_2$의 반응을 통해 탄산칼슘을 제조한다. 이 기술은 파일럿 단계까지 기술개발이 진행되었으며(알토대학교의 Slag2PCC), 상용화를 위해서는 경제성 증대가 필요할 것으로 판단된다. 개발을 위한 핵심 기술로는 슬래그로부터 Ca의 효과적 용출 및 불순물 제거, 탄산칼슘의 입도 및 입형 제어를 통한 고부가가치화, 잔사 슬래그의 활용방안 발굴, 연속공정 구현을 위한 반응 조건최적화 등을 들 수 있다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.1023-1030
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• 2005

This study is an experiment paper about the ground improvement material which using the waste residual(slag and paper fly ash) by fire. we are research to concern according to the soil to mix the ground improvement material at show strength effectiveness. Also, we can expect a long time strength increase effectiveness as reduce the dryness contraction. They are distinguished to the clay of the reclamation ground and silty sand soil. We examined around an uniaxial compress test and scanning electron microscopy. The uniaxial stress increases according to the increase of the mixed ratio of ground improvement material and the water contents have been reduced the strength value. A clay's improvement effectiveness is big but in the silty sand soil to express small effectiveness. A ground improvement material mixing of the quantity to write can not expect the effect of Ettringite.